Marital aggression and head injury represent significant health problems, yet they have received inadequate attention and are poorly understood. The interface between these topics has been virtually ignored. Although organic factors are normally an important part of the bio-psycho-social traid invoked to explain human behavior, to date they have been omitted from research and theorizing in the marital aggression area. The aim of the proposed investigation is to examine the relationship between head injury and marital aggression. Two related studies are being proposed. The first study will evaluate the prevalence of head injury and neurological deficits in a sample of wife-abusive men and two comparison samples of non-abusive men: maritally discordant men and satisfactorily married men. It is hypothesized that wife-abusive men will have a significantly higher prevalence of head trauma and that subsample of batterers with neuropsychological deficits will be identified. In the second study patients who have been medically treated for head injuries will be identified from hospital records and will be assessed for occurrence of aggression. Wives of the subjects will be asked to provide information concerning their spouse's behavior. A comparison group of non-head trauma patients and their wives will be assessed with the expectation that they will evidence a lower prevalence of post-injury aggression marital and otherwise. One concern regarding the design of the first study is the possibility that a third factor produces both marital aggression and an increased probability of head injury. Study 2 will help to clarify this by assessing the occurrence of aggression both pre-and post-injury. Failure to find pre-post differences in aggressiveness would support third factor explanations. A positive finding of such differences would support the importance of organic factors as contributors to the production of aggression. Both studies will try to identify whether there are parameters of head injury that are associated with the occurrence of marital aggression. An important goal will be the introduction of organic factors into our etiological models of marital aggression. These studies will provide important leads that will stimulate further research in this potentially important domain and may eventuate in preventive interventions and biomedical treatment approaches.